Method for manufacturing micro-structure

Abstract

A micro-structure is manufactured by patterning a sacrificial film, forming an inorganic material film on the pattern, providing the inorganic material film with an aperture, and etching away the sacrificial film pattern through the aperture to define a space having the contour of the pattern. The patterning stage includes the steps of (A) forming a sacrificial film using a composition comprising a cresol novolac resin and a crosslinker, (B) exposing patternwise the film to first high-energy radiation, (C) developing, and (D) exposing the sacrificial film pattern to second high-energy radiation and heat treating for thereby forming crosslinks within the cresol novolac resin.

What is claimed is: 
     
       1. An optically patternable sacrificial film-forming composition for use in surface micro-machining process, comprising
 (A-1) (i) a cresol novolac resin consisting of at least 40 mol % of p-cresol and the remainder of m-cresol and having a weight average molecular weight of 2,000 to 30,000 and a melting temperature of at least 130° C. in which some or all phenolic hydroxyl groups are esterified with 1,2-naphthoquinonediazidosulfonyl halide, or (ii) a mixture of the cresol novolac resin consisting of at least 40 mol % of p-cresol and the remainder of m-cresol and having a weight average molecular weight of 2,000 to 30,000 and having some or all phenolic hydroxyl groups esterified with 1,2-naphthoquinonediazidosulfonyl halide and a cresol novolac resin consisting of at least 40 mol % of p-cresol and the remainder of m-cresol and having a weight average molecular weight of 2,000 to 30,000 and a melting temperature of at least 130° C. in which phenolic hydroxyl groups are not esterified, or (A-2) the novolac resin (i) or the novolac resin mixture (ii) of (A-1) and a 1,2-naphthoquinonediazidosulfonic acid ester, and 
 a crosslinker capable of foiiiiing crosslinks within the cresol novolac resin in the presence of an acid catalyst. 
 
     
     
       2. The composition of  claim 1  wherein the content of component (A-1) or (A-2) is 45 to 98% by weight in the total solids weight of the sacrificial film-forming composition, and the total amount of the esterized cresol novolac resin and the non-esterized cresol novolac resin is at least 67% by weight in component (A-1) or (A-2). 
     
     
       3. The composition of  claim 1  wherein said crosslinker is a melamine compound and said sacrificial film-forming composition comprises 2 to 30% by weight of the melamine compound in the total solids weight of the composition. 
     
     
       4. The composition of  claim 1  wherein a cresol novolac resin in which 1 to 30 mol % of phenolic hydroxyl groups are esterified with 1,2-naphthoquinonediazidosulfonyl halide is present. 
     
     
       5. The composition of  claim 1  which further comprises at least one photoacid generator selected from the group consisting of oximesulfonates and imid-yl-sulfonate derivatives. 
     
     
       6. The composition of  claim 5  wherein the photoacid generator is selected from the group consisting of 4-methoxy-α-(p-toluenesulfonyloxyimino)phenylacetonitrile, α-(4-toluenesulfonyloxyimino)-3-thienylacetonitrile, 1,8-naphthalimide-10-camphorsulfonate, 1,8-naphthalimide-10-p-toluenesulfonate, and 5-norbornene-2,3-dicarboxyimid-yl-n-butylsulfonate. 
     
     
       7. A material for manufacturing a micro-structure comprising a substrate and a sacrificial film formed thereon,
 said sacrificial film comprising the optically patternable sacrificial film-forcing composition of  claim 1 . 
 
     
     
       8. A material for manufacturing a micro-structure comprising a substrate and a sacrificial film pattern formed thereon,
 said sacrificial film pattern being formed from the sacrificial film comprising the optically patternable sacrificial film-forming composition of  claim 1 . 
 
     
     
       9. The material of  claim 7 , wherein the sacrificial film has a thickness of 2.0 to 20 μm. 
     
     
       10. The material of  claim 8 , wherein the sacrificial film has a sidewall angle from 80°to less than 90°. 
     
     
       11. The composition of  claim 1 , wherein component (A-1) is (i) a cresol novolac resin consisting of at least 40 mol % of p-cresol and the remainder of m-cresol and having a weight average molecular weight of 2,000 to 30,000 and a melting temperature of at least 130° C. in which some or all phenolic hydroxyl groups are esterified with 1,2-naphthoquinonediazidosulfonyl halide. 
     
     
       12. The composition of  claim 1 , comprising:
 (A-1) (i) a cresol novolac resin consisting of at least 40 mol % of p-cresol and the remainder of m-cresol and having a weight average molecular weight of 2,000 to 30,000and a melting temperature of at least 130° C. in which some or all phenolic hydroxyl groups are esterified with 1,2-naphthoquinonediazidosulfonyl halide, or (ii) a mixture of the cresol novolac resin consisting of at least 40 mol % of p-cresol and the remainder of m-cresol and having a weight average molecular weight of 2,000 to 30,000 and having some or all phenolic hydroxyl groups esterified with 1,2-naphthoquinonediazidosulfonyl halide and a cresol novolac resin consisting of at least 40 mol % of p-cresol and the remainder of m-cresol and having a weight average molecular weight of 2,000 to 30,000 and a melting temperature of at least 130° C. in which phenolic hydroxyl groups are not esterified, and 
 a crosslinker capable of forming crosslinks within the cresol novolac resin in the presence of an acid catalyst.